As part of the work on transitioning bufferization dialect, ops, and
associated logic to operate on newly added type interfaces (see
00eaff3e9c897c263a879416d0f151d7ca7eeaff), rename the
bufferization.to_memref to highlight the generic nature of the op.
Bufferization process produces buffers while memref is a builtin type
rather than a generic term.
Preserve the current API (to_buffer still produces a memref), however,
as the new type interfaces are not used yet.
`getDescriptorFromTensorTuple` and `getMutDescriptorFromTensorTuple`
extract the tensor type from an `unrealized_conversion_cast` op that
serves as a workaround for missing 1:N dialect conversion support.
This commit changes these functions so that they explicitly receive the
tensor type as a function argument. This is in preparation of merging
the 1:1 and 1:N conversion drivers. The conversion patterns in this file
will soon start receiving multiple SSA values (`ValueRange`) from their
adaptors (instead of a single value that is the result of
`unrealized_conversion_cast`). It will no longer be possible to take the
tensor type from the `unrealized_conversion_cast` op. The
`unrealized_conversion_cast` workaround will disappear entirely.
Separates actual transformation files from supporting utility files in
the transforms directory. Includes a bazel overlay fix for the build (as
well as a bit of cleanup of that file to be less verbose and more
flexible).
